Edexcel IGCSE Chemistry 復(fù)習(xí)筆記 2.5.1 Sources of Metals
Edexcel IGCSE Chemistry 復(fù)習(xí)筆記 2.5.1 Sources of Metals
Sources of Metals
- The Earth’s crust contains metals and metal compounds such as gold, copper, iron oxide and aluminium oxide
- Useful metals are often?chemically combined?with other substances forming?ores
- A metal ore is a rock that contains enough of the metal to make it worthwhile extracting
- They have to be extracted from their ores through processes such as?electrolysis, using a?blast?furnace?or by reacting with?more?reactive?material
- In many cases the ore is an?oxide?of the metal, therefore the extraction of these metals is a reduction process since oxygen is being removed
- Common examples of oxide ores are?iron?and?aluminium?ores which are called?haematite?and?bauxite?respectively
- Unreactive metals do not have to be extracted chemically as they are often found as the?uncombined?element
- This occurs as they do not easily react with other substances due to their?chemical?stability
- Examples include?gold?and?platinum?which can both be mined directly from the Earth’s crust
Exam Tip
A metal can reduce another metal (remove oxygen) only if it is more reactive than the metal that is bonded to the oxygen.
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